Silencer.



R. J. 'MAcKENZlE & L. L. HAAS.

SILENCER.

APPLICATION HLED AUG-24. 1916.

Patented Sept. 17,1918

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UNITED STATES PATENT OFFICE.

Ra J. MACKENZIE Ann LUCIEN L. HAAS, 0F BUFFALO, NEW YORK, ASSIGNORS ToBUFFALO PRESSED STEEL COMPANY, OF BUFFALO, NEW YORK.

SILENCER To all whom it may concern:

Be it known that we, ROYJ. MAoKENzIE andLUCIEN L. H'AAS, citizens of theUnited States, residing at Buffalo, in the county of Erie and State ofNew York, have invented a new and useful Improvement in Silencers,of'which the following is a specification.

This invention relates to mutllers or silencers such as are connectedwith the exhausts of internal combustion engines for reducing the noiseincident to the explosions. These devices ordinarily comprise a casingthrough which the exhaust gases from the engine pass, and battles ofsome sort in the casing which intercept the gases or prevent the directflow of the same through the casing.

One object of this inventionis to produce a practical and efii-cientsilencer of this character which will give the maximum silencing effectwith the minimum back pressure and which is so constructed that theparts can be manufactured and assembled with the minimum expense andlabor and so that the parts can expand and contract freely under thechanges in temperature to which they are subjected in use whilenevertheless being held firmly in place and prevented from rattling.Another object is to produce a construction enabling the parts of thesilencer to be made at small expense from sheet metal and securetogether without. the use of bolts or other additional fasteningdevices.

In the accompanying drawings:

Figure 1 is a longitudinal sectional elevation of a silencer embodyingthe invention.

Fig. 2 is an enlarged fragmentary section thereof showing the battles insection and the slpacing pieces removed.

Figs. 3 and 41 are transverse sectional elevations thereof on lines 3-3,and 4-4, Fig.

1, -respectively, looking in the directions in-.

dicated by the arrows.

Fig. 5 is a fragmentary transverse'sectional elevation thereof on line5-5, Fig. 1, in the direction indicated by the arrow.

The casing of the silencer is preferably composed of a cylindrical openended sheet metal body 1 and sheet metal ends or heads 2 and 3 which aresecured in thebody by spinning or turning the ends of the latterREISSUED Specification of Letters Patent. Patented Sept. 1'7, 1918.Application filed August 24, 1916.

Serial No. 116,720.

over marginal flanges 4 on the heads. By thus securing the heads in thecylinder a flangeden(:l casing of strong rigid construct n is producedand the heads can be forced toward each other by the spinning of theends of the body to the extent necessary to compress and firmly holdtogether the parts in the cylinder as hereinafter explained. 5 and 6indicate respectively inlet and dis charge t-ubes'o'r connections on theopposite ends of the casing. These tubes are preferably fixed in holesin the ends of the casing by proi iding beads 7 on the tubes and flang-.ing or spinnlng the ends of the tubes to clamp the edges of the holesin the heads tightly between the beads and flanges.

8 represents batlies or plates, of which there are a plurality arrangedcrosswise in the casing at suitable intervals, and 9 is an inner orsilencing tube or cylinder extending lengthwise in, the casing betweentwo of the baflie plates and forming an annular space 10 in the casingaround the inner tube.

The bafiie plates which are preferably sheet. metal stampings, areformed with dished or frusto-conical central portions .11 and the twobatfle plates at the ends of the silencing tube 9 are oppositelyarranged with their dished central ortions extending into the ends ofthe tube whereby the latter is held in place.

The battle plates 8 are spaced from each other and from the ends of thecasing by spacing rings or devices 12 and 13 which are preferably formedby zig-zag strips of sheet metal bent into and secured in circular orring shape. The walls of these rings are corrugated lengthwise and arebowed so that the spacing rings are of smaller diameter' at their endsthan between their ends.-

The spacing devices bear at their ends against the baflie plates, oragainst the baffle plates and ends of the casing in the case of the twodevices located at the ends of the casing, and bear between their endsagainst the cylindrical wall of the casing. When the parts are placed inthe casing and the ends of the casing spun over the flanges of the heads2 and 3 to secure the latter, the spacing devices are compressed'endwise and bulged or expanded crosswise so as to fit snugly in thecasing and bear firmly against the baflie plates and ends of the easing,and the extent of this COIHPI'QSSIOII is determined as required by theamount which the ends of the casing are spun over. The spacing devicesare resilient and act as springs to hold the baiile plates and silencingtube in connection and in place in the casing and to permit expansionand contraction of the parts due to changes in temperature without,allowing the parts to become loose or to rattle. In assembling the partsit is thus only necessary to place them n the proper order in the casingand spin over the ends of the casing to secure them, and no bolts orother fastening devices are required This greatly simplifies the laborand expense of assembling and reduces the number and cost of the parts.The spacing device 12 between the inlet end of the casing and the firstbaffle plate is ordinarily longer than the other spacing devices andprovides a large expansion chamber 14 for.

the gases in advance of the silencing tube. The openings between thestaggered points at opposite ends of the spacing devices permit thepassage of gases, and the spacing devices therefore also act assilencing devices or battles to the fiow'of the gases.

The bafiie plates and silencing tube 9 are provided with holes oropenings for the passage of the gases, the number and arrangement of theholes being such asto break up the gases into numerous small streamswhich fiow in differentor opposing directions and more or less interceptor conflict with each other, thereby resulting in a thorough breaking upand churning of the gases in the easing. As shown, the baffle plate atthe inlet end of the inner tube 9 has holes 15, which may be of anysuitable number and size, in its central portion so as to direct thegases into the inner tube, and the other holes 15 in their centralportions and in addition are provided in their outer portions with twoseries of slits l6 and partially punched-out parts or vanes 17 whichface in opposite directions and cause the streams of gases passingthrough the slits to flow in opposite or conflicting directions in thecasing. The inner tube is also provided with two or more circumferentialrows of analogous slits 18 and vanes 19, the vanes in one series facingoppositely to those of the next series so as to cause. the streams ofgases passing through the slits to whirl in opposite directions in thespace 10 around,

the silencing tube.

The number and spacing of the bafiie plates and the lengths of thespacing devicesand of thesilencing tube may be varied to suit differentengines, the numbers and proportioning of the parts depending upon therequirements of the engines with which the silencers are to be used.Likewise-the therein providing passages for gases, and spacing devicesarranged between the baflies and between the ends of the casing and theadjacent batiies, said spacing devices consisting of compressible andexpansible rings which bear at their ends against said battles and theends of the casing and between their ends against the walls of thecasing.

3. A silencer comprising" a casing, spaced battles therein providingpassages for gases, and devices'for spacing the bafiles in the casingeach consisting of an annular zig-zag strip which is bowedlongitudinally.

4. A silencer comprising a casin. spaced baflles therein providingpassagesor gases, and devices for spacing the bafiles in the casing eachconsisting of an annular zigzag strip which is corrugated longitudinaland is bowed outwardly between its ends to ward the walls of the casing.

5. A silencer comprising a casing, spaced baflies therein providingpassages for gases,

and a tube whlch is arranged lengthwise in said casing between twoof'said bafiies and forms an annular space in the casin said tube havingpassages for the gases an parts which cause the gases to whirl inopposite directions in said annular passage. bafile plates are similarlyprovided with 6. A silencer comprising a casin spaced bafiies thereinproviding passages or gases, and a tube which is arranged lengthwise insaid casing between two of said bafiies and forms an annular space inthe casing, said tube having passages for the gases and said tube andbaiiies having parts which cause the gases to whirl in oppositedirections in the casing.

7. A silencer comprising a casing, spaced bafiles therein providingpassa es for gases,

. having projecting portions entering the ends of said tube, andmeansfor pressing said baiiles yicldingiy toward the ends of said tubefor holding the parts firmly together.

9. A silencer comprising a casing having a body and heads, bafiles inthe casing. yielding means for spacing the battles and yieldinglyresisting movement of said bafilcs toward each other, and means at oneend of the casing for forcing one of said heads inwardly to compress theparts in the casing between the heads of the casing.

10. A silencer comprising a casing having a body and heads, baffles inthe casing, and yielding means for spacing the bafiies and yieldinglyresisting movement of said bafiies toward each other, one end of saidbody being spun over for securing the adjacent head on the casin andcompressing the parts in the casing tween the heads of the casing.

11. A silencer comprising a casing. and spaced baflies in the casinproviding passages for gases, said bafiies consisting of sheet metalplates having perforated dished central portions, and surrounding outerportions having openings therethrough and vanes adjacent said openingswhich face alternately in substantially opposite tangential directionsfor causing the gases to whirl in opposite directions in the casing.

12. A silencer comprising a casing, bafiies therein providing passagesfor gases, and compressible and expansible devices arranged between saidbaflies and acting to space said baiiies and yieldingly resist relativemovement thereof, and means for holding the parts with said devicesunder compression.

13. A silencer comprising a casing, baflies therein providing passagesfor gases, and

compressible and eXpansible devices arranged between said baiiles andacting to space said battles and yieldingly resist relative movementthereof, and means for holding the parts with said devices undercompression, said devices also providing passages forthe gases andacting as bafiies.

Witness our hands, this 18th day of Au gust, 1916.

ROY J. MAcKENZIE. LUCIEN L. HAAS.

Witnesses:

THEODORE C. WILLIS, E. E. SPANGLE.

